Electric aeg lamp



2 Sheets-Sheet 1.

W. J. DAVY.

ELECTRIC ARC LAMP.

'IIII WITNESSES m5 NNNNNNNNNNNNNNNNNNNNNNNNNNN Y.

(No Model.) 2 Sheets-Sheet 2.

W. J. DAVY.

ELECTRIC ARC LAMP.

No. 521,877. Patented June 26,1894.

. 4 F .8 1 29.7. a'J W 101mm MMM NNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Y UNITEDSTATES PATENT OFFICE.

WILLIAM J. DAVY, OF LONDON, ENGLAND.

ELECTRIC-ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 521,877, dated June 26,1894.

Application filed April 14, 1 894. Serial No. 507,611. (No model.)

To all whom it may concern.-

Be it known that I, WILLIAM JAMES DAVY, a subject of the Queen of GreatBritain, residing at 161 l-Iuddleston Road, Tufnel Park, London, in thecounty of Middlesex, England, have invented certain new and usefulImprovements in Electric-Arc Lamps; and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and use the same.

This invention for improvements in electric arc lamps relates tofocusing lamps in which the positive and negative carbon holders areconnected together by a cord passing over a pulley and in which theupper carbon holder tends to descend by gravity and thus at the sametime to draw up thelower carbon holder so as to bring the two carbonsinto contact; and consists in an improved arrangement for striking andmaintaining constant the arc consisting of a gravity friction gripdevice acting on the cord and regulated by series and shunt solenoids.

In the accompanying two sheets of illustrative drawings:-Figure 1 is anelevation, the hood shades, solenoids and friction grip brake beingsupposed removed, of a single lamp constructed according to thisinvention. Fig. 2 is a sectional elevation of the solenoids and frictiongrip brake. Fig. 3 is a plan of the upper part of the lamp with the hoodremoved. Fig. 4 is a plan of the travelers and their guides and of thesolenoids. Fig. 5 is an elevation of the gravity friction grip device,and Fig. 6 is a plan of the same. Fig. 7 is a sectional elevation of aduplex lamp constructed according to this invention and Fig. 8 is a planof the upper part of the lamp and of the friction grip devices, and Fig.9 is a plan of the travelers and its guides and the solenoids.

The guide rods a for the lower carbon traveler b and the guide rods 0for the upper carbon traveler d are secured to the non conducting disks2 and f, the distance between the rods a. and also between the rods 0being determined by the tie washers Mounted in projections dependingfrom a saddle bracket h secured to the disk e is a spindle c whichcarries the loose cord pulleys 7' and the fixed regulating brake leversconnected by links at one end to the core lof the series solenoid m andat the other end to the core a of the shunt solenoid 0 both solenoidsbeing carried from the under side of the disk 6.

By using non-conducting disks or supports the several parts of the lampare thoroughly insulated from one another and a sound solid frameobtained.

The upper carbon traveler cl is guided by means of small grooved rollers19 fixed at the extremities of the traveler d and bearingon the rods 0and carries the upper carbon holder q. The lower carbon traveler b isguided by a single grooved roller 7' mounted at its upper end andbearing between the two rods a and is attached to a depending tail rod 3having a tapered end on which is secured the lower carbon holder t bythe fly nut u. The two travelers b d are connected together by the cordw passing over the loose pulleyj and between the friction grip devicecarried by the lovers 7c. The guiding arrangement allows of the use oflonger carbons or the reduction of the length of the lamp and the methodof attaching the lower carbon holder enables the carbons to be easilyset in line.

The friction grip device consists of the four pairs of links 1, 2, 3,and 4 jointed together at the points 5, 6, '7, and 8 and suspended fromthe regulating levers k at the point 5 at a slight distance from thespindle iforming the fulcrum of the regulating levers k. Each pair oflower links carries a jaw or grip 9 between which the cord w passes.Normally the jaws rest on the plate e.

The operation of the grip device is as fol- 1oWs:-On the current passingto the lamp the core Z of the series solenoid m is drawn down and bymeans of the regulating leverk draws up the point of support 5 of thefriction grip links. This motion of the point 5 causes the jaws 9 togrip the cord to the jaws still resting on the plate 6. jaws grip thecord the relative motion of the points 5, 8 is stopped and the wholefriction grip device is raised with the point 5 and raises with it thecord w and so the arc is struck. As the resistance of the arc increasesdue to the burning away of the carbons and consequent lengthening ofthe-arc the power of the series solenoid decreases and gradually thefriction grip device is lowered on to the As soon as the 5 plate e andthe jaws begin to relax their hold on the cord to and a continuous andsteady feed isobtained by the cord feeding slowly through the jaws 9. Ifthe lamp is working in series the shunt solenoid 0 which is connectedacross the terminals of the lamp helps to feed the carbons together andmaintain a steady are. In order to still further increase the steadinessof the arc the piston of a dash pot m is attached by a link to theregulating lever 76.

The duplex lamp shown in Figs. 7, 8, and 9, is actuated by one strikingand regulating mechanism there being two sets of travelers b b and d dand carbons, two cords to w and pulleys j j and two friction gripdevices actuated by one set of regulating levers k and solenoidsmo. Theduplicate parts are similar to those described for the single lamp andare indicated respectively by the same reference letters the second setbeing indicated by a dash to the letter. Also two series cores Z1 andsolenoids m m acting together are shown. The lamp is suspended by theeye A screwed into the saddle, bracket 72 and secured by a lock nut. Thehood B fits over the eye A and is secured by the milled nut O. The bellhood D flanges into and depends from the plate 6 and is secured by thehood B whose lower edge passes over the upper edge of the bell hood D asclearly shown. The cover and hood can thus be firmly fixed or removed byhand without removing the conducting wires. The spring clips E forcarrying the globe F are riveted to the bell hood D. The reflector orshade G is hooked over the lips of the globe F. A mica disk H protectsthe lower disk f and thus the working parts of the lamp from injury fromthe ascending gases from the arc. The current enters the lamp at l,thence through the series coil m to the holders of the upper carbonsthrough the carbons-tail rods and holders for the lower carbons to theterminal J. The shunt coil 0 is connected across the terminals I J inthe usual manner. The friction grip devices of the two sets of carbonsare arranged so that one set when the regulating levers k are actuatedleaves the disk e before the other.

The operation of the duplex lamp is as follows: On the current passingto the lamp the regulating levers la raise the friction grip devices andthe first to leave the plate a simply separates the correspondingcarbons leaving the first pair of carbons-that is the pair to be firsteonsumedstill in contact. On the further motion of the regulating leverthe friction grip devices of the first pair of carbons leaves the diske, separates the points of the carbons and strikes and maintains thearc.

During the time that the first set of carbons grip devices until thesecond device comes in contact with the disk and releases the secondcord of the second set of carbons which then come in contact and thefirst set are immediately extinguished. The regulating levers It thenagain raise the grip devices and strike the are for the second pair ofcarbons which continue to burn until completely consumed. In asimilarmanner alamp with three or more pairs of carbons can be operated by asingle striking and regulating mechanism.

As shown the upper or positive carbon is double the size of the lower ornegative carbon so that the focus of the lamp is constant. Inalternating current lamps the carbons may be of the same size.

What I claim, and desire to secure by Letters Patent, is

1. In electric arc lamps in which the positive and negative holders areconnected together by a cord passing over a pulley and in which thetendency of the carbon holders is to approach, the gravity friction gripdevice consisting of a system of links pivoted together to form a closedframe, of grip jaws between which passes the part of the cord orconnecting device tending to move downward and which are attached to thejointed frame in such position that they approach one another as theframe elongates in a vertical direction, of a stop on which the lowerend of the link frame rests and of a means for determining the positionof the upper end of the frame relatively to the said stop according tothe resistance of the lamp substantially as set forth.

2. In electric arc lamps in which the positive and negative holders areconnected together by a cord passing -over a pulley and in which thetendency of the carbon holders is to approach, the gravity friction gripdevice consisting of a lever mounted on the spindle of the loose cordpulley, of a means for determining the position of one end of the leveraccording to the resistance of the lamp, of a system of links suspendedfrom the le- Ver and pivoted together to form a closed frame, of gripjaws between which passes the part of the cord or connecting devicetending to move downward and which are attached to the jointed frame insuch position that they approach one another as the frame elongates in avertical direction, and of a stop on which the lower end of the linkframe rests substantially as set forth.

3. In electric arc lamps in which the positive and negative holders areconnected together by a cord passing over a pulley and in which thetendency of the carbon holders is to approach, the are striking andmaintaining mechanism consisting of a lever mounted on the spindle of aloose cord pulley, of a solenoid core attached to the lever, of acorresponding solenoid arranged in series, of a system of linkssuspended from the lever in such manner that they are raised when asolenoid core is drawn into its coil and piv- IIO oted together to forma closed frame, of grip jaws between which passes the part of the cordor connecting device tending to move downward and which are attached tothe jointed frame in such position that they approach one another as theframe elongates in a vertical direction and of a stop on which the lowerend of thelink frame rests, substantially as set forth.

4. In electric arc lamps in which each positive holder is connected tothe corresponding negative holder by a cord passing over a pulley and inwhich the tendency of the carbons is to approach, a series of gravityfriction grip devices one for each pair of carbons and each deviceconsisting of a system of links pivoted together to form a closed frame,of grip jaws between which passes the part of the cord or connectingdevice tending to move downward and which are attached to the jointedframe in such position that they approach one another as the frameelongates in a vertical direction, of a single stop on which the lowerends of the links rest, and of a means whereby the upper ends of theframes are raised together to aheight dependent on the current throughthe lamp the said devices being so connected to the said means that theyare successively raised olf the said stop, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

W. J. DAVY..

Witnesses:

GEO. J. B. FRANKLIN, WALTER J. SKERTEN.

